Plastic explosive mixture of high shattering power



' PatentedJuly 12, 1932 PATENT OFFICE ALFRED STETTIBAGHER, OF ZURICH,SWITZERLAND PLASTIC EXPLOSIVE MIXTURE OF HIGH SHATTERING POWER NoDrawing. Application filed June 16, 1930, Serial No. 461,652, and inSwitzerland February 27, 1930.

In the course of further researches concerning the explosive mixture,which forms the object of the application No. 363,999, 1 filed May 17,1929 it has become evident that 5 it may be desirable for military aswell as for industrial purposes to deprive the said mixture (whichconsists of crystalline pentaerythrite tetranitrate and'liquid aliphaticnitric acid esters of polyvalent alcohols, such as nitroglycerine,dinitroglycol, or a mixture of both) of its oily character partly orwholly by adding collodion-cotton in a quantity corresponding to 0.5 to8 of the liquid nitrate constituents. The collodion-cotton is preferablyfirst completely saturated with the liquid nitric acid esters and thismixture in a cold or heated state and partly or totally gelatinized isthen mixed with the powdery pentaerythrite tetranitrate and kneaded.This composition is known as penthrinite. Its sensitiveness againstshocks can be reduced below that of the shock-proof and shotresistingpicric acid by adding to the liquid nitric acid esters, prior togelatinizing, a phlegmatizing agent soluble in the latter, such ascamphor, and a stabilizing agent such as for instance Centralite orurethane. Centralite is dimethyl-diphenyl-urea. At the same time theexplosive mass becomes more plastic and tough and acquires such astability that it can be stored indefinitely, although possessing asuperior explosive power than the charges of projectiles hithertogenerally utilized. Such a gelatinized penthrinite differs from theknown explosive gelatine (nitrogelatine) and all the other specialexplosive gelatines (nitrogelatines), in that it does not age, i. e. itretains unaltered its extraordinary detonation velocity during anylength of storage.

According to the required purposes the filling of projectiles,aero-shells, hand-grenades, mines etc. may be done before or afterswelling takes place. If, for instance, the pressing or casting of themixture is done in a cold condition, then the gelatination takes placeslowly and will become complete, according to the temperature of the dayand the proportion of nitroglycol within from a few hours to some weeks.The advantage nitric acid ester of polyvalent aliphatic alcoobtained bythe addition of collodion-cotton consists chiefly in the fixation of theliquid constituents which renders possible the employment ofpenthrinites containing a large proportion of nitroglycerine and being,therefore, particularly efiicient.

The following is an example of an explosive mixture according to thepresent in vention.

EwampZe.- to 5% of a not easily congealable liquid mixture consisting of75% nitroglycerine and 25% nitroglycol in which 0 to 6% camphor with orwithout 0.1 to 3.0% Centralite or urethane has been previously dissolvedand in which thereupon, in a cold condition or after heating, 8 to 0.1%collodion-cotton has been incorporated, is mixed with 5 to 95%pentaerythrite tetranitrate.

What I claim is 1. A plastic explosive mixture detonating withmaximumvelocity, suitable for military purposes, consisting of a mixture of 5to 95 parts by weight of pentaerythrite-tetranitrate with 95 to 5 partsby weight of a liquid hols, and 8 to 0.1% collodion-cotton.

2. A process of manufacturing a plastic, explosive composition whichconsists in mixing 5 to 95 parts of pentaerythrite-tetranitrate with 95to 5 parts all by weight of a liquid nitric acid ester of polyvalentaliphatic alcohols, to which 8 to 0.1% of collodioncotton has previouslybeen added.

3. A process as described in claim 2 in which camphor as phlegmatizingagent up to 6% is added prior to the gelatination with collodion-cotton.

4. A process as described in claim 2 in which camphor as phlegmatizingagent up to 6% is added prior to the gelatination with collodion-cotton,in which prior to gelatination and phlegmatizing a stabilizing medium isdissolved in the liquid ester-component at the ratio of 0.1 to 3%.

In testimony whereof I have signed my name to this specification.

ALFRED STETTBACHER.

